/*******************************************************************************
 * Copyright (c) 2013, Daniel Murphy
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 	* Redistributions of source code must retain the above copyright notice,
 * 	  this list of conditions and the following disclaimer.
 * 	* Redistributions in binary form must reproduce the above copyright notice,
 * 	  this list of conditions and the following disclaimer in the documentation
 * 	  and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 ******************************************************************************/

/*
 * JBox2D - A Java Port of Erin Catto's Box2D
 * 
 * JBox2D homepage: http://jbox2d.sourceforge.net/
 * Box2D homepage: http://www.box2d.org
 * 
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * 
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */
package org.jbox2d.collision;

/** Contact ids to facilitate warm starting. Note: the ContactFeatures class is just embedded in here */
public class ContactID implements Comparable<ContactID> {

	public static enum Type {
		VERTEX, FACE
	}

	public byte indexA;
	public byte indexB;
	public byte typeA;
	public byte typeB;

	public int getKey () {
		return ((int)indexA) << 24 | ((int)indexB) << 16 | ((int)typeA) << 8 | ((int)typeB);
	}

	public boolean isEqual (final ContactID cid) {
		return getKey() == cid.getKey();
	}

	public ContactID () {
	}

	public ContactID (final ContactID c) {
		set(c);
	}

	public void set (final ContactID c) {
		indexA = c.indexA;
		indexB = c.indexB;
		typeA = c.typeA;
		typeB = c.typeB;
	}

	public void flip () {
		byte tempA = indexA;
		indexA = indexB;
		indexB = tempA;
		tempA = typeA;
		typeA = typeB;
		typeB = tempA;
	}

	/** zeros out the data */
	public void zero () {
		indexA = 0;
		indexB = 0;
		typeA = 0;
		typeB = 0;
	}

	@Override
	public int compareTo (ContactID o) {
		return getKey() - o.getKey();
	}
}
